The core components of the U.S.-Japan security alliance – power projection, control of the seas, and deterrence – are intrinsically related to sea power. Yet even though maritime cooperation is part of a larger framework of security collaboration, there is little spillover from the two countries’ joint efforts on nontraditional security issues to conventional security concerns. This could change as two new traditionally land-based powers – China and Russia – begin to turn their attention to the seas. The prospect of a melting Arctic Ocean, creating new sea routes, makes such efforts even more compelling.